A catalogue of unusual phobias reveals that the fear of long words is known as hippopotomonstrosesquippedaliophobia.

The condition, sometimes shortened to sesquippedaliophobia, can leave sufferers with shortness of breath, rapid breathing, an irregular heartbeat, sweating, nausea, and overall feelings of dread.

Among the bizarre crippling dreads listed on changethatsrightnow.com are the ridiculous sounding zemmiphobia, or fear of the great mole rat, and alektorophobia, or a fear of chickens.

Those with lutraphobia fear otters, those with globophobia fear balloons and those with pteronophobia fear of being tickled by feathers.

Generations of comedians would have struggled for jokes without pentheraphobia - fear of the mother-in-law, while fear of France and French culture is termed Genuphobia.

Doctors define a phobia as “a constant, extreme or irrational fear of an animal, object, place or situation” that would not normally worry most people.

The fears often develop in late childhood, adolescence or early adulthood, sometimes in response to a frightening event.

While some people who have phobias of objects or situations they rarely encounter, for example snakes, can frequently live their lives normally, other sufferers of complex phobias like agoraphobia - a fear of being away from home, can find it very difficult to lead a normal life.

The mental health charity Mind estimates there are more than 10 million people who suffer from phobias, though fear of admitting a problem makes it difficult to judge true figures.

Simple phobias involve a fear of specific, particular objects, situations or activities, with some of the most common instances being insects, rats, germs, enclosed spaces, heights or flying.

Complex phobias such as agoraphobia, can involve several linked fears.

Professor Robert Edelmann, patron of the National Phobics Society, said: “It would be unusual to find someone who doesn’t have some fears about something, but it is a smaller number of people who have disabling clinical phobias.”

He said while a phobia of being tickled by feather may sound unusual he could enviasge someone having a phobia if for example as a child they were tickeld when they did not want to be and did not like it.

He said he himself had treated people who were anxious of clowns, which was not too distant from a fear of balloons.

He said: “The list for potential phobias is actually quite long.”

One thoery of how phobias develop is that people are biologically programmed to be afraid of certain things.

Prof Edelmann said: “It might have been useful for our prehistoric ancestors to fear the dark, when they might be attacked or to fear little animals that dash about which could harm them.”

A spokesman for the website said it had not treated people for all the phobias listed and fear of public speaking was among the most common with clients.

He said: “On a regular basis we tend to deal with perhaps 15 of the phobias.”